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mariadb/sql/filesort.cc
unknown 6a868cca91 Fixed warnings from valgrind (not a bug) 
Don't add -debug to server version if MYSQL_SERVER_PREFIX is used
Indentation cleanups


myisam/mi_write.c:
  Indentation cleanup
mysql-test/r/lowercase_table2.result:
  Fixed test results
sql/filesort.cc:
  Fixed warnings from valgrind (not a bug)
sql/ha_myisam.cc:
  Indentation cleanup
sql/mysqld.cc:
  Don't add -debug to server if MYSQL_SERVER_PREFIX is used
sql/sql_base.cc:
  Indentation cleanup
sql/sql_show.cc:
  Fixed typo in comment
sql/sql_table.cc:
  Indentation cleanup
2004-04-06 12:13:43 +03:00

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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Sorts a database */
#include "mysql_priv.h"
#ifdef HAVE_STDDEF_H
#include <stddef.h> /* for macro offsetof */
#endif
#include <m_ctype.h>
#include "sql_sort.h"
#ifndef THREAD
#define SKIP_DBUG_IN_FILESORT
#endif
/* How to write record_ref. */
#define WRITE_REF(file,from) \
if (my_b_write((file),(byte*) (from),param->ref_length)) \
DBUG_RETURN(1);
/* functions defined in this file */
static char **make_char_array(register uint fields, uint length, myf my_flag);
static BUFFPEK *read_buffpek_from_file(IO_CACHE *buffer_file, uint count);
static ha_rows find_all_keys(SORTPARAM *param,SQL_SELECT *select,
uchar * *sort_keys, IO_CACHE *buffer_file,
IO_CACHE *tempfile,IO_CACHE *indexfile);
static int write_keys(SORTPARAM *param,uchar * *sort_keys,
uint count, IO_CACHE *buffer_file, IO_CACHE *tempfile);
static void make_sortkey(SORTPARAM *param,uchar *to, byte *ref_pos);
static int merge_index(SORTPARAM *param,uchar *sort_buffer,
BUFFPEK *buffpek,
uint maxbuffer,IO_CACHE *tempfile,
IO_CACHE *outfile);
static bool save_index(SORTPARAM *param,uchar **sort_keys, uint count);
static uint sortlength(SORT_FIELD *sortorder, uint s_length,
bool *multi_byte_charset);
static SORT_ADDON_FIELD *get_addon_fields(THD *thd, Field **ptabfield,
uint sortlength, uint *plength);
static void unpack_addon_fields(struct st_sort_addon_field *addon_field,
byte *buff);
/*
Sort a table
SYNOPSIS
filesort()
table Table to sort
sortorder How to sort the table
s_length Number of elements in sortorder
select condition to apply to the rows
special Not used.
(This could be used to sort the rows pointed on by
select->file)
examined_rows Store number of examined rows here
IMPLEMENTATION
Creates a set of pointers that can be used to read the rows
in sorted order. This should be done with the functions
in records.cc
REQUIREMENTS
Before calling filesort, one must have done
table->file->info(HA_STATUS_VARIABLE)
RETURN
HA_POS_ERROR Error
# Number of rows
examined_rows will be set to number of examined rows
The result set is stored in table->io_cache or
table->record_pointers
*/
ha_rows filesort(THD *thd, TABLE *table, SORT_FIELD *sortorder, uint s_length,
SQL_SELECT *select, ha_rows max_rows, ha_rows *examined_rows)
{
int error;
ulong memavl, min_sort_memory;
uint maxbuffer;
BUFFPEK *buffpek;
ha_rows records= HA_POS_ERROR;
uchar **sort_keys;
IO_CACHE tempfile, buffpek_pointers, *selected_records_file, *outfile;
SORTPARAM param;
bool multi_byte_charset;
DBUG_ENTER("filesort");
DBUG_EXECUTE("info",TEST_filesort(sortorder,s_length););
#ifdef SKIP_DBUG_IN_FILESORT
DBUG_PUSH(""); /* No DBUG here */
#endif
outfile= table->sort.io_cache;
my_b_clear(&tempfile);
my_b_clear(&buffpek_pointers);
buffpek=0;
sort_keys= (uchar **) NULL;
error= 1;
bzero((char*) &param,sizeof(param));
param.sort_length= sortlength(sortorder, s_length, &multi_byte_charset);
param.ref_length= table->file->ref_length;
param.addon_field= 0;
param.addon_length= 0;
if (!(table->tmp_table || table->fulltext_searched))
{
/*
Get the descriptors of all fields whose values are appended
to sorted fields and get its total length in param.spack_length.
*/
param.addon_field= get_addon_fields(thd, table->field,
param.sort_length,
&param.addon_length);
}
table->sort.addon_buf= 0;
table->sort.addon_length= param.addon_length;
table->sort.addon_field= param.addon_field;
table->sort.unpack= unpack_addon_fields;
if (param.addon_field)
{
param.res_length= param.addon_length;
if (!(table->sort.addon_buf= (byte *) my_malloc(param.addon_length,
MYF(MY_WME))))
goto err;
}
else
{
param.res_length= param.ref_length;
/*
The reference to the record is considered
as an additional sorted field
*/
param.sort_length+= param.ref_length;
}
param.rec_length= param.sort_length+param.addon_length;
param.max_rows= max_rows;
if (select && select->quick)
{
statistic_increment(filesort_range_count, &LOCK_status);
}
else
{
statistic_increment(filesort_scan_count, &LOCK_status);
}
#ifdef CAN_TRUST_RANGE
if (select && select->quick && select->quick->records > 0L)
{
records=min((ha_rows) (select->quick->records*2+EXTRA_RECORDS*2),
table->file->records)+EXTRA_RECORDS;
selected_records_file=0;
}
else
#endif
{
records=table->file->estimate_number_of_rows();
selected_records_file= 0;
}
if (multi_byte_charset &&
!(param.tmp_buffer=my_malloc(param.sort_length,MYF(MY_WME))))
goto err;
memavl= thd->variables.sortbuff_size;
min_sort_memory= max(MIN_SORT_MEMORY, param.sort_length*MERGEBUFF2);
while (memavl >= min_sort_memory)
{
ulong old_memavl;
ulong keys= memavl/(param.rec_length+sizeof(char*));
param.keys=(uint) min(records+1, keys);
if ((sort_keys= (uchar **) make_char_array(param.keys, param.rec_length,
MYF(0))))
break;
old_memavl=memavl;
if ((memavl=memavl/4*3) < min_sort_memory && old_memavl > min_sort_memory)
memavl= min_sort_memory;
}
if (memavl < min_sort_memory)
{
my_error(ER_OUTOFMEMORY,MYF(ME_ERROR+ME_WAITTANG),
thd->variables.sortbuff_size);
goto err;
}
if (open_cached_file(&buffpek_pointers,mysql_tmpdir,TEMP_PREFIX,
DISK_BUFFER_SIZE, MYF(MY_WME)))
goto err;
param.keys--; /* TODO: check why we do this */
param.sort_form= table;
param.end=(param.local_sortorder=sortorder)+s_length;
if ((records=find_all_keys(&param,select,sort_keys, &buffpek_pointers,
&tempfile, selected_records_file)) ==
HA_POS_ERROR)
goto err;
maxbuffer= (uint) (my_b_tell(&buffpek_pointers)/sizeof(*buffpek));
if (maxbuffer == 0) // The whole set is in memory
{
if (save_index(&param,sort_keys,(uint) records))
goto err;
}
else
{
if (!(buffpek=read_buffpek_from_file(&buffpek_pointers, maxbuffer)))
goto err;
close_cached_file(&buffpek_pointers);
/* Open cached file if it isn't open */
if (! my_b_inited(outfile) &&
open_cached_file(outfile,mysql_tmpdir,TEMP_PREFIX,READ_RECORD_BUFFER,
MYF(MY_WME)))
goto err;
reinit_io_cache(outfile,WRITE_CACHE,0L,0,0);
/*
Use also the space previously used by string pointers in sort_buffer
for temporary key storage.
*/
param.keys=((param.keys*(param.rec_length+sizeof(char*))) /
param.rec_length-1);
maxbuffer--; // Offset from 0
if (merge_many_buff(&param,(uchar*) sort_keys,buffpek,&maxbuffer,
&tempfile))
goto err;
if (flush_io_cache(&tempfile) ||
reinit_io_cache(&tempfile,READ_CACHE,0L,0,0))
goto err;
if (merge_index(&param,(uchar*) sort_keys,buffpek,maxbuffer,&tempfile,
outfile))
goto err;
}
if (records > param.max_rows)
records=param.max_rows;
error =0;
err:
if (param.tmp_buffer)
x_free(param.tmp_buffer);
x_free((gptr) sort_keys);
x_free((gptr) buffpek);
close_cached_file(&tempfile);
close_cached_file(&buffpek_pointers);
if (my_b_inited(outfile))
{
if (flush_io_cache(outfile))
error=1;
{
my_off_t save_pos=outfile->pos_in_file;
/* For following reads */
if (reinit_io_cache(outfile,READ_CACHE,0L,0,0))
error=1;
outfile->end_of_file=save_pos;
}
}
if (error)
my_error(ER_FILSORT_ABORT,MYF(ME_ERROR+ME_WAITTANG));
else
statistic_add(filesort_rows, (ulong) records, &LOCK_status);
*examined_rows= param.examined_rows;
#ifdef SKIP_DBUG_IN_FILESORT
DBUG_POP(); /* Ok to DBUG */
#endif
DBUG_PRINT("exit",("records: %ld",records));
DBUG_RETURN(error ? HA_POS_ERROR : records);
} /* filesort */
void filesort_free_buffers(TABLE *table)
{
if (table->sort.record_pointers)
{
my_free((gptr) table->sort.record_pointers,MYF(0));
table->sort.record_pointers=0;
}
if (table->sort.addon_buf)
{
my_free((char *) table->sort.addon_buf, MYF(0));
my_free((char *) table->sort.addon_field, MYF(MY_ALLOW_ZERO_PTR));
table->sort.addon_buf=0;
table->sort.addon_field=0;
}
}
/* Make a array of string pointers */
static char **make_char_array(register uint fields, uint length, myf my_flag)
{
register char **pos;
char **old_pos,*char_pos;
DBUG_ENTER("make_char_array");
if ((old_pos= (char**) my_malloc((uint) fields*(length+sizeof(char*)),
my_flag)))
{
pos=old_pos; char_pos=((char*) (pos+fields)) -length;
while (fields--) *(pos++) = (char_pos+= length);
}
DBUG_RETURN(old_pos);
} /* make_char_array */
/* Read all buffer pointers into memory */
static BUFFPEK *read_buffpek_from_file(IO_CACHE *buffpek_pointers, uint count)
{
ulong length;
BUFFPEK *tmp;
DBUG_ENTER("read_buffpek_from_file");
tmp=(BUFFPEK*) my_malloc(length=sizeof(BUFFPEK)*count, MYF(MY_WME));
if (tmp)
{
if (reinit_io_cache(buffpek_pointers,READ_CACHE,0L,0,0) ||
my_b_read(buffpek_pointers, (byte*) tmp, length))
{
my_free((char*) tmp, MYF(0));
tmp=0;
}
}
DBUG_RETURN(tmp);
}
/* Search after sort_keys and place them in a temp. file */
static ha_rows find_all_keys(SORTPARAM *param, SQL_SELECT *select,
uchar **sort_keys,
IO_CACHE *buffpek_pointers,
IO_CACHE *tempfile, IO_CACHE *indexfile)
{
int error,flag,quick_select;
uint idx,indexpos,ref_length;
byte *ref_pos,*next_pos,ref_buff[MAX_REFLENGTH];
my_off_t record;
TABLE *sort_form;
volatile bool *killed= &current_thd->killed;
handler *file;
DBUG_ENTER("find_all_keys");
DBUG_PRINT("info",("using: %s",(select?select->quick?"ranges":"where":"every row")));
idx=indexpos=0;
error=quick_select=0;
sort_form=param->sort_form;
file=sort_form->file;
ref_length=param->ref_length;
ref_pos= ref_buff;
quick_select=select && select->quick;
record=0;
flag= ((!indexfile && file->table_flags() & HA_REC_NOT_IN_SEQ)
|| quick_select);
if (indexfile || flag)
ref_pos= &file->ref[0];
next_pos=ref_pos;
if (! indexfile && ! quick_select)
{
file->reset(); // QQ; Shouldn't be needed
if (sort_form->key_read) // QQ Can be removed after the reset
file->extra(HA_EXTRA_KEYREAD); // QQ is removed
next_pos=(byte*) 0; /* Find records in sequence */
file->rnd_init();
file->extra_opt(HA_EXTRA_CACHE,
current_thd->variables.read_buff_size);
}
for (;;)
{
if (quick_select)
{
if ((error=select->quick->get_next()))
break;
file->position(sort_form->record[0]);
}
else /* Not quick-select */
{
if (indexfile)
{
if (my_b_read(indexfile,(byte*) ref_pos,ref_length)) /* purecov: deadcode */
{
error= my_errno ? my_errno : -1; /* Abort */
break;
}
error=file->rnd_pos(sort_form->record[0],next_pos);
}
else
{
error=file->rnd_next(sort_form->record[0]);
if (!flag)
{
ha_store_ptr(ref_pos,ref_length,record); // Position to row
record+=sort_form->db_record_offset;
}
else
file->position(sort_form->record[0]);
}
if (error && error != HA_ERR_RECORD_DELETED)
break;
}
if (*killed)
{
DBUG_PRINT("info",("Sort killed by user"));
(void) file->extra(HA_EXTRA_NO_CACHE);
file->rnd_end();
DBUG_RETURN(HA_POS_ERROR); /* purecov: inspected */
}
if (error == 0)
param->examined_rows++;
if (error == 0 && (!select || select->skip_record() == 0))
{
if (idx == param->keys)
{
if (write_keys(param,sort_keys,idx,buffpek_pointers,tempfile))
DBUG_RETURN(HA_POS_ERROR);
idx=0;
indexpos++;
}
make_sortkey(param,sort_keys[idx++],ref_pos);
}
else
file->unlock_row();
}
(void) file->extra(HA_EXTRA_NO_CACHE); /* End cacheing of records */
file->rnd_end();
DBUG_PRINT("test",("error: %d indexpos: %d",error,indexpos));
if (error != HA_ERR_END_OF_FILE)
{
file->print_error(error,MYF(ME_ERROR | ME_WAITTANG)); /* purecov: inspected */
DBUG_RETURN(HA_POS_ERROR); /* purecov: inspected */
}
if (indexpos && idx &&
write_keys(param,sort_keys,idx,buffpek_pointers,tempfile))
DBUG_RETURN(HA_POS_ERROR); /* purecov: inspected */
DBUG_RETURN(my_b_inited(tempfile) ?
(ha_rows) (my_b_tell(tempfile)/param->rec_length) :
idx);
} /* find_all_keys */
/* Skriver en buffert med nycklar till filen */
static int
write_keys(SORTPARAM *param, register uchar **sort_keys, uint count,
IO_CACHE *buffpek_pointers, IO_CACHE *tempfile)
{
uint sort_length, rec_length;
uchar **end;
BUFFPEK buffpek;
DBUG_ENTER("write_keys");
sort_length= param->sort_length;
rec_length= param->rec_length;
#ifdef MC68000
quicksort(sort_keys,count,sort_length);
#else
my_string_ptr_sort((gptr) sort_keys, (uint) count, sort_length);
#endif
if (!my_b_inited(tempfile) &&
open_cached_file(tempfile, mysql_tmpdir, TEMP_PREFIX, DISK_BUFFER_SIZE,
MYF(MY_WME)))
goto err; /* purecov: inspected */
buffpek.file_pos= my_b_tell(tempfile);
if ((ha_rows) count > param->max_rows)
count=(uint) param->max_rows; /* purecov: inspected */
buffpek.count=(ha_rows) count;
for (end=sort_keys+count ; sort_keys != end ; sort_keys++)
if (my_b_write(tempfile, (byte*) *sort_keys, (uint) rec_length))
goto err;
if (my_b_write(buffpek_pointers, (byte*) &buffpek, sizeof(buffpek)))
goto err;
DBUG_RETURN(0);
err:
DBUG_RETURN(1);
} /* write_keys */
/* makes a sort-key from record */
static void make_sortkey(register SORTPARAM *param,
register uchar *to, byte *ref_pos)
{
reg3 Field *field;
reg1 SORT_FIELD *sort_field;
reg5 uint length;
for (sort_field=param->local_sortorder ;
sort_field != param->end ;
sort_field++)
{
bool maybe_null=0;
if ((field=sort_field->field))
{ // Field
if (field->maybe_null())
{
if (field->is_null())
{
if (sort_field->reverse)
bfill(to,sort_field->length+1,(char) 255);
else
bzero((char*) to,sort_field->length+1);
to+= sort_field->length+1;
continue;
}
else
*to++=1;
}
field->sort_string((char*) to,sort_field->length);
}
else
{ // Item
Item *item=sort_field->item;
switch (sort_field->result_type) {
case STRING_RESULT:
{
CHARSET_INFO *cs=item->collation.collation;
char fill_char= ((cs->state & MY_CS_BINSORT) ? (char) 0 : ' ');
if ((maybe_null=item->maybe_null))
*to++=1;
/* All item->str() to use some extra byte for end null.. */
String tmp((char*) to,sort_field->length+4,cs);
String *res=item->val_str(&tmp);
if (!res)
{
if (item->maybe_null)
bzero((char*) to-1,sort_field->length+1);
else
{
DBUG_PRINT("warning",
("Got null on something that shouldn't be null"));
bzero((char*) to,sort_field->length); // Avoid crash
}
break;
}
length=res->length();
int diff=(int) (sort_field->length-length);
if (diff < 0)
{
diff=0; /* purecov: inspected */
length=sort_field->length;
}
if (sort_field->need_strxnfrm)
{
char *from=(char*) res->ptr();
if ((unsigned char *)from == to)
{
set_if_smaller(length,sort_field->length);
memcpy(param->tmp_buffer,from,length);
from=param->tmp_buffer;
}
uint tmp_length=my_strnxfrm(cs,to,sort_field->length,
(unsigned char *) from, length);
if (tmp_length < sort_field->length)
cs->cset->fill(cs, (char*) to+tmp_length,
sort_field->length-tmp_length,
fill_char);
}
else
{
my_strnxfrm(cs,(uchar*)to,length,(const uchar*)res->ptr(),length);
cs->cset->fill(cs, (char *)to+length,diff,fill_char);
}
break;
}
case INT_RESULT:
{
longlong value=item->val_int();
if ((maybe_null=item->maybe_null))
*to++=1; /* purecov: inspected */
if (item->null_value)
{
if (item->maybe_null)
bzero((char*) to-1,sort_field->length+1);
else
{
DBUG_PRINT("warning",
("Got null on something that shouldn't be null"));
bzero((char*) to,sort_field->length);
}
break;
}
#if SIZEOF_LONG_LONG > 4
to[7]= (uchar) value;
to[6]= (uchar) (value >> 8);
to[5]= (uchar) (value >> 16);
to[4]= (uchar) (value >> 24);
to[3]= (uchar) (value >> 32);
to[2]= (uchar) (value >> 40);
to[1]= (uchar) (value >> 48);
to[0]= (uchar) (value >> 56) ^ 128; // Fix sign
#else
to[3]= (uchar) value;
to[2]= (uchar) (value >> 8);
to[1]= (uchar) (value >> 16);
to[0]= (uchar) (value >> 24) ^ 128; // Fix sign
#endif
break;
}
case REAL_RESULT:
{
double value=item->val();
if ((maybe_null=item->null_value))
{
bzero((char*) to,sort_field->length+1);
to++;
break;
}
if ((maybe_null=item->maybe_null))
*to++=1;
change_double_for_sort(value,(byte*) to);
break;
}
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
break;
}
}
if (sort_field->reverse)
{ /* Revers key */
if (maybe_null)
to[-1]= ~to[-1];
length=sort_field->length;
while (length--)
{
*to = (uchar) (~ *to);
to++;
}
}
else
to+= sort_field->length;
}
if (param->addon_field)
{
/*
Save field values appended to sorted fields.
First null bit indicators are appended then field values follow.
In this implementation we use fixed layout for field values -
the same for all records.
*/
SORT_ADDON_FIELD *addonf= param->addon_field;
uchar *nulls= to;
DBUG_ASSERT(addonf);
bzero((char *) nulls, addonf->offset);
to+= addonf->offset;
for ( ; (field= addonf->field) ; addonf++)
{
if (addonf->null_bit && field->is_null())
{
nulls[addonf->null_offset]|= addonf->null_bit;
#ifdef HAVE_purify
bzero(to, addonf->length);
#endif
}
else
{
uchar *end= (uchar*) field->pack((char *) to, field->ptr);
#ifdef HAVE_purify
uint length= (uint) ((to + addonf->length) - end);
DBUG_ASSERT((int) length >= 0);
if (length)
bzero(end, length);
#endif
}
to+= addonf->length;
}
}
else
{
/* Save filepos last */
memcpy((byte*) to, ref_pos, (size_s) param->ref_length);
}
return;
}
static bool save_index(SORTPARAM *param, uchar **sort_keys, uint count)
{
uint offset,res_length;
byte *to;
DBUG_ENTER("save_index");
my_string_ptr_sort((gptr) sort_keys, (uint) count, param->sort_length);
res_length= param->res_length;
offset= param->rec_length-res_length;
if ((ha_rows) count > param->max_rows)
count=(uint) param->max_rows;
if (!(to= param->sort_form->sort.record_pointers=
(byte*) my_malloc(res_length*count, MYF(MY_WME))))
DBUG_RETURN(1); /* purecov: inspected */
for (uchar **end= sort_keys+count ; sort_keys != end ; sort_keys++)
{
memcpy(to, *sort_keys+offset, res_length);
to+= res_length;
}
DBUG_RETURN(0);
}
/* Merge buffers to make < MERGEBUFF2 buffers */
int merge_many_buff(SORTPARAM *param, uchar *sort_buffer,
BUFFPEK *buffpek, uint *maxbuffer, IO_CACHE *t_file)
{
register int i;
IO_CACHE t_file2,*from_file,*to_file,*temp;
BUFFPEK *lastbuff;
DBUG_ENTER("merge_many_buff");
if (*maxbuffer < MERGEBUFF2)
DBUG_RETURN(0); /* purecov: inspected */
if (flush_io_cache(t_file) ||
open_cached_file(&t_file2,mysql_tmpdir,TEMP_PREFIX,DISK_BUFFER_SIZE,
MYF(MY_WME)))
DBUG_RETURN(1); /* purecov: inspected */
from_file= t_file ; to_file= &t_file2;
while (*maxbuffer >= MERGEBUFF2)
{
reinit_io_cache(from_file,READ_CACHE,0L,0,0);
reinit_io_cache(to_file,WRITE_CACHE,0L,0,0);
lastbuff=buffpek;
for (i=0 ; i <= (int) *maxbuffer-MERGEBUFF*3/2 ; i+=MERGEBUFF)
{
if (merge_buffers(param,from_file,to_file,sort_buffer,lastbuff++,
buffpek+i,buffpek+i+MERGEBUFF-1,0))
break; /* purecov: inspected */
}
if (merge_buffers(param,from_file,to_file,sort_buffer,lastbuff++,
buffpek+i,buffpek+ *maxbuffer,0))
break; /* purecov: inspected */
if (flush_io_cache(to_file))
break; /* purecov: inspected */
temp=from_file; from_file=to_file; to_file=temp;
*maxbuffer= (uint) (lastbuff-buffpek)-1;
}
close_cached_file(to_file); // This holds old result
if (to_file == t_file)
*t_file=t_file2; // Copy result file
DBUG_RETURN(*maxbuffer >= MERGEBUFF2); /* Return 1 if interrupted */
} /* merge_many_buff */
/* Read data to buffer */
/* This returns (uint) -1 if something goes wrong */
uint read_to_buffer(IO_CACHE *fromfile, BUFFPEK *buffpek,
uint rec_length)
{
register uint count;
uint length;
if ((count=(uint) min((ha_rows) buffpek->max_keys,buffpek->count)))
{
if (my_pread(fromfile->file,(byte*) buffpek->base,
(length= rec_length*count),buffpek->file_pos,MYF_RW))
return((uint) -1); /* purecov: inspected */
buffpek->key=buffpek->base;
buffpek->file_pos+= length; /* New filepos */
buffpek->count-= count;
buffpek->mem_count= count;
}
return (count*rec_length);
} /* read_to_buffer */
/*
Merge buffers to one buffer
*/
int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
IO_CACHE *to_file, uchar *sort_buffer,
BUFFPEK *lastbuff, BUFFPEK *Fb, BUFFPEK *Tb,
int flag)
{
int error;
uint rec_length,sort_length,res_length,offset;
ulong maxcount;
ha_rows max_rows,org_max_rows;
my_off_t to_start_filepos;
uchar *strpos;
BUFFPEK *buffpek,**refpek;
QUEUE queue;
qsort2_cmp cmp;
volatile bool *killed= &current_thd->killed;
bool not_killable;
DBUG_ENTER("merge_buffers");
statistic_increment(filesort_merge_passes, &LOCK_status);
if (param->not_killable)
{
killed= &not_killable;
not_killable= 0;
}
error=0;
rec_length= param->rec_length;
res_length= param->res_length;
sort_length= param->sort_length;
offset= rec_length-res_length;
maxcount= (ulong) (param->keys/((uint) (Tb-Fb) +1));
to_start_filepos= my_b_tell(to_file);
strpos= (uchar*) sort_buffer;
org_max_rows=max_rows= param->max_rows;
if (init_queue(&queue, (uint) (Tb-Fb)+1, offsetof(BUFFPEK,key), 0,
(queue_compare) (cmp= get_ptr_compare(sort_length)),
(void*) &sort_length))
DBUG_RETURN(1); /* purecov: inspected */
for (buffpek= Fb ; buffpek <= Tb ; buffpek++)
{
buffpek->base= strpos;
buffpek->max_keys= maxcount;
strpos+= (uint) (error= (int) read_to_buffer(from_file, buffpek,
rec_length));
if (error == -1)
goto err; /* purecov: inspected */
buffpek->max_keys= buffpek->mem_count; // If less data in buffers than expected
queue_insert(&queue, (byte*) buffpek);
}
if (param->unique_buff)
{
/*
Called by Unique::get()
Copy the first argument to param->unique_buff for unique removal.
Store it also in 'to_file'.
This is safe as we know that there is always more than one element
in each block to merge (This is guaranteed by the Unique:: algorithm
*/
buffpek= (BUFFPEK*) queue_top(&queue);
memcpy(param->unique_buff, buffpek->key, rec_length);
if (my_b_write(to_file, (byte*) buffpek->key, rec_length))
{
error=1; goto err; /* purecov: inspected */
}
buffpek->key+= rec_length;
buffpek->mem_count--;
if (!--max_rows)
{
error= 0; /* purecov: inspected */
goto end; /* purecov: inspected */
}
queue_replaced(&queue); // Top element has been used
}
else
cmp= 0; // Not unique
while (queue.elements > 1)
{
if (*killed)
{
error= 1; goto err; /* purecov: inspected */
}
for (;;)
{
buffpek= (BUFFPEK*) queue_top(&queue);
if (cmp) // Remove duplicates
{
if (!(*cmp)(&sort_length, &(param->unique_buff),
(uchar**) &buffpek->key))
goto skip_duplicate;
memcpy(param->unique_buff, (uchar*) buffpek->key, rec_length);
}
if (flag == 0)
{
if (my_b_write(to_file,(byte*) buffpek->key, rec_length))
{
error=1; goto err; /* purecov: inspected */
}
}
else
{
if (my_b_write(to_file, (byte*) buffpek->key+offset, res_length))
{
error=1; goto err; /* purecov: inspected */
}
}
if (!--max_rows)
{
error= 0; /* purecov: inspected */
goto end; /* purecov: inspected */
}
skip_duplicate:
buffpek->key+= rec_length;
if (! --buffpek->mem_count)
{
if (!(error= (int) read_to_buffer(from_file,buffpek,
rec_length)))
{
uchar *base= buffpek->base;
ulong max_keys= buffpek->max_keys;
VOID(queue_remove(&queue,0));
/* Put room used by buffer to use in other buffer */
for (refpek= (BUFFPEK**) &queue_top(&queue);
refpek <= (BUFFPEK**) &queue_end(&queue);
refpek++)
{
buffpek= *refpek;
if (buffpek->base+buffpek->max_keys*rec_length == base)
{
buffpek->max_keys+= max_keys;
break;
}
else if (base+max_keys*rec_length == buffpek->base)
{
buffpek->base= base;
buffpek->max_keys+= max_keys;
break;
}
}
break; /* One buffer have been removed */
}
else if (error == -1)
goto err; /* purecov: inspected */
}
queue_replaced(&queue); /* Top element has been replaced */
}
}
buffpek= (BUFFPEK*) queue_top(&queue);
buffpek->base= sort_buffer;
buffpek->max_keys= param->keys;
/*
As we know all entries in the buffer are unique, we only have to
check if the first one is the same as the last one we wrote
*/
if (cmp)
{
if (!(*cmp)(&sort_length, &(param->unique_buff), (uchar**) &buffpek->key))
{
buffpek->key+= rec_length; // Remove duplicate
--buffpek->mem_count;
}
}
do
{
if ((ha_rows) buffpek->mem_count > max_rows)
{ /* Don't write too many records */
buffpek->mem_count= (uint) max_rows;
buffpek->count= 0; /* Don't read more */
}
max_rows-= buffpek->mem_count;
if (flag == 0)
{
if (my_b_write(to_file,(byte*) buffpek->key,
(rec_length*buffpek->mem_count)))
{
error= 1; goto err; /* purecov: inspected */
}
}
else
{
register uchar *end;
strpos= buffpek->key+offset;
for (end= strpos+buffpek->mem_count*rec_length ;
strpos != end ;
strpos+= rec_length)
{
if (my_b_write(to_file, (byte *) strpos, res_length))
{
error=1; goto err;
}
}
}
}
while ((error=(int) read_to_buffer(from_file,buffpek, rec_length))
!= -1 && error != 0);
end:
lastbuff->count= min(org_max_rows-max_rows, param->max_rows);
lastbuff->file_pos= to_start_filepos;
err:
delete_queue(&queue);
DBUG_RETURN(error);
} /* merge_buffers */
/* Do a merge to output-file (save only positions) */
static int merge_index(SORTPARAM *param, uchar *sort_buffer,
BUFFPEK *buffpek, uint maxbuffer,
IO_CACHE *tempfile, IO_CACHE *outfile)
{
DBUG_ENTER("merge_index");
if (merge_buffers(param,tempfile,outfile,sort_buffer,buffpek,buffpek,
buffpek+maxbuffer,1))
DBUG_RETURN(1); /* purecov: inspected */
DBUG_RETURN(0);
} /* merge_index */
/*
Calculate length of sort key
SYNOPSIS
sortlength()
sortorder Order of items to sort
uint s_length Number of items to sort
multi_byte_charset (out)
Set to 1 if we are using multi-byte charset
(In which case we have to use strxnfrm())
NOTES
sortorder->length is updated for each sort item
sortorder->need_strxnfrm is set 1 if we have to use strxnfrm
RETURN
Total length of sort buffer in bytes
*/
static uint
sortlength(SORT_FIELD *sortorder, uint s_length, bool *multi_byte_charset)
{
reg2 uint length;
THD *thd= current_thd;
CHARSET_INFO *cs;
*multi_byte_charset= 0;
length=0;
for (; s_length-- ; sortorder++)
{
sortorder->need_strxnfrm= 0;
if (sortorder->field)
{
if (sortorder->field->type() == FIELD_TYPE_BLOB)
sortorder->length= thd->variables.max_sort_length;
else
{
sortorder->length=sortorder->field->pack_length();
if (use_strnxfrm((cs=sortorder->field->charset())))
{
sortorder->need_strxnfrm= 1;
*multi_byte_charset= 1;
sortorder->length= sortorder->length*cs->strxfrm_multiply;
}
}
if (sortorder->field->maybe_null())
length++; // Place for NULL marker
}
else
{
switch ((sortorder->result_type=sortorder->item->result_type())) {
case STRING_RESULT:
sortorder->length=sortorder->item->max_length;
if (use_strnxfrm((cs=sortorder->item->collation.collation)))
{
sortorder->length= sortorder->length*cs->strxfrm_multiply;
sortorder->need_strxnfrm= 1;
*multi_byte_charset= 1;
}
break;
case INT_RESULT:
#if SIZEOF_LONG_LONG > 4
sortorder->length=8; // Size of intern longlong
#else
sortorder->length=4;
#endif
break;
case REAL_RESULT:
sortorder->length=sizeof(double);
break;
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
break;
}
if (sortorder->item->maybe_null)
length++; // Place for NULL marker
}
set_if_smaller(sortorder->length, thd->variables.max_sort_length);
length+=sortorder->length;
}
sortorder->field= (Field*) 0; // end marker
DBUG_PRINT("info",("sort_length: %d",length));
return length;
}
/*
Get descriptors of fields appended to sorted fields and
calculate its total length
SYNOPSIS
get_addon_fields()
thd Current thread
ptabfields Array of references to the table fields
sortlength Total length of sorted fields
plength out: Total length of appended fields
DESCRIPTION
The function first finds out what fields are used in the result set.
Then it calculates the length of the buffer to store the values of
these fields together with the value of sort values.
If the calculated length is not greater than max_length_for_sort_data
the function allocates memory for an array of descriptors containing
layouts for the values of the non-sorted fields in the buffer and
fills them.
NOTES
The null bits for the appended values are supposed to be put together
and stored the buffer just ahead of the value of the first field.
RETURN
Pointer to the layout descriptors for the appended fields, if any
NULL - if we do not store field values with sort data.
*/
static SORT_ADDON_FIELD *
get_addon_fields(THD *thd, Field **ptabfield, uint sortlength, uint *plength)
{
Field **pfield;
Field *field;
SORT_ADDON_FIELD *addonf;
uint length= 0;
uint fields= 0;
uint null_fields= 0;
/*
If there is a reference to a field in the query add it
to the the set of appended fields.
Note for future refinement:
This this a too strong condition.
Actually we need only the fields referred in the
result set. And for some of them it makes sense to use
the values directly from sorted fields.
*/
*plength= 0;
/*
The following statement is added to avoid sorting in alter_table.
The fact is the filter 'field->query_id != thd->query_id'
doesn't work for alter table
*/
if (thd->lex->sql_command != SQLCOM_SELECT)
return 0;
for (pfield= ptabfield; (field= *pfield) ; pfield++)
{
if (field->query_id != thd->query_id)
continue;
if (field->flags & BLOB_FLAG)
return 0;
length+= field->max_packed_col_length(field->pack_length());
if (field->maybe_null())
null_fields++;
fields++;
}
if (!fields)
return 0;
length+= (null_fields+7)/8;
if (length+sortlength > thd->variables.max_length_for_sort_data ||
!(addonf= (SORT_ADDON_FIELD *) my_malloc(sizeof(SORT_ADDON_FIELD)*
(fields+1), MYF(MY_WME))))
return 0;
*plength= length;
length= (null_fields+7)/8;
null_fields= 0;
for (pfield= ptabfield; (field= *pfield) ; pfield++)
{
if (field->query_id != thd->query_id)
continue;
addonf->field= field;
addonf->offset= length;
if (field->maybe_null())
{
addonf->null_offset= null_fields/8;
addonf->null_bit= 1<<(null_fields & 7);
null_fields++;
}
else
{
addonf->null_offset= 0;
addonf->null_bit= 0;
}
addonf->length= field->max_packed_col_length(field->pack_length());
length+= addonf->length;
addonf++;
}
addonf->field= 0; // Put end marker
DBUG_PRINT("info",("addon_length: %d",length));
return (addonf-fields);
}
/*
Copy (unpack) values appended to sorted fields from a buffer back to
their regular positions specified by the Field::ptr pointers.
SYNOPSIS
unpack_addon_fields()
addon_field Array of descriptors for appended fields
buff Buffer which to unpack the value from
NOTES
The function is supposed to be used only as a callback function
when getting field values for the sorted result set.
RETURN
void.
*/
static void
unpack_addon_fields(struct st_sort_addon_field *addon_field, byte *buff)
{
Field *field;
SORT_ADDON_FIELD *addonf= addon_field;
for ( ; (field= addonf->field) ; addonf++)
{
if (addonf->null_bit && (addonf->null_bit & buff[addonf->null_offset]))
{
field->set_null();
continue;
}
field->set_notnull();
field->unpack(field->ptr, (char *) buff+addonf->offset);
}
}
/*
** functions to change a double or float to a sortable string
** The following should work for IEEE
*/
#define DBL_EXP_DIG (sizeof(double)*8-DBL_MANT_DIG)
void change_double_for_sort(double nr,byte *to)
{
uchar *tmp=(uchar*) to;
if (nr == 0.0)
{ /* Change to zero string */
tmp[0]=(uchar) 128;
bzero((char*) tmp+1,sizeof(nr)-1);
}
else
{
#ifdef WORDS_BIGENDIAN
memcpy_fixed(tmp,&nr,sizeof(nr));
#else
{
uchar *ptr= (uchar*) &nr;
#if defined(__FLOAT_WORD_ORDER) && (__FLOAT_WORD_ORDER == __BIG_ENDIAN)
tmp[0]= ptr[3]; tmp[1]=ptr[2]; tmp[2]= ptr[1]; tmp[3]=ptr[0];
tmp[4]= ptr[7]; tmp[5]=ptr[6]; tmp[6]= ptr[5]; tmp[7]=ptr[4];
#else
tmp[0]= ptr[7]; tmp[1]=ptr[6]; tmp[2]= ptr[5]; tmp[3]=ptr[4];
tmp[4]= ptr[3]; tmp[5]=ptr[2]; tmp[6]= ptr[1]; tmp[7]=ptr[0];
#endif
}
#endif
if (tmp[0] & 128) /* Negative */
{ /* make complement */
uint i;
for (i=0 ; i < sizeof(nr); i++)
tmp[i]=tmp[i] ^ (uchar) 255;
}
else
{ /* Set high and move exponent one up */
ushort exp_part=(((ushort) tmp[0] << 8) | (ushort) tmp[1] |
(ushort) 32768);
exp_part+= (ushort) 1 << (16-1-DBL_EXP_DIG);
tmp[0]= (uchar) (exp_part >> 8);
tmp[1]= (uchar) exp_part;
}
}
}
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